Method for producing levulinic acid by efficiently catalyzing saccharides

Abstract

The invention discloses a method for efficiently catalyzing saccharides to produce levulinic acid, which specifically comprises the following steps: preparing a reaction system from a strongly acidic solid catalyst, the saccharides and acetic acid or an aqueous solution thereof, carrying out heating reaction, and after the reaction is finished, carrying out solid-liquid separation on the reaction system to obtain the levulinic acid. According to the method, acetic acid is adopted as a catalytic solvent, wherein weak coordination of acetic acid can retain high acidity of a strong acid catalyst in a system, so that the reaction conditions are mild, catalytic activity is high, acetic acid has certain solubility to saccharides, a certain amount of water is added, and the saccharide treatment capacity is large. In addition, the acetic acid is wide in source, low in price, low in evaporation heat and low in product separation cost, and favorable conditions are provided for economic recovery of levulinic acid.

Description

technical field [0001] The invention belongs to the field of catalytic utilization of biomass, and in particular relates to a method for efficiently catalyzing carbohydrates to produce levulinic acid. Background technique [0002] Levulinic acid is an important biomass-based platform compound. It contains a carboxyl group and a ketone carbonyl group. It can undergo various reactions such as esterification, decarboxylation, oxidation, reduction, and carbon-carbon bond coupling to generate a variety of chemicals and energy. substances, and their efficient, economical and green synthesis has received more and more attention. [0003] Levulinic acid is currently mostly synthesized from biomass-based sugars or their derivatives such as furfural and 5-hydroxymethylfurfural through multi-step catalytic conversion. The formation of levulinic acid from furfural is essentially a hydration process. During the reaction, the carbon number of the molecule remains unchanged, the reaction ...

AI Technical Summary

Problems solved by technology

The formation of levulinic acid from furfural is essentially a hydration process. During the reaction, the carbon number of the molecule remains unchanged, the reaction conditions are mild, and the yield is high. However, furfural itself is an important biomass-based platform compound. It is derived from Biomass-based hemicellulose is produced by acid-catalyzed dehydration, the production cost is high, and the process route of its conversion to levulinic acid is not economical

5-Hydroxymethylfurfural is also a biomass-based platform molecule. Compared with furfural, its raw material sources are wider. It can be synthesized from cellulose or monosaccharides through acid-catalyzed conversion, but 5-Hydroxymethylfurfural The same production cost is high, and the economics of preparing levulinic acid is similar to that of furfural.

However, the key issue in the relevant technological process is not the yield, but the concentration of levulinic acid generated in the reaction process is often very low, mostly around 5%, and some are even lower than 1%, and levulinic acid is miscible with water. It is difficult to separate levulinic acid from the water phase system, and the water in the system can be removed by means of distillation in time, but the separation of levulinic acid and catalysts such as sulfuric acid is also a great difficulty

In addition, due to the low catalytic activity of catalysts in aqueous systems, these processes often require higher reaction temperatures.

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